ICM254 Fan Blower Control Delay Timer -How to convert it to 12V DC

strantor

Joined Oct 3, 2010
6,782
if that thing has a simple coil inside, you could use 12VDC by this method. but, if it's got circuitry inside it (which I highly suspect) then all bets are off. Seems to be a fairly inexpensive relay and if you have a boat then the assumption is that you have enough money to not go hungry if you burned that relay up. if it were my relay, I would just go for it; if it burns up, hey, you needed to buy a different one anyway.
 

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Manfred Von Steinborn

Joined Feb 3, 2009
38
I called the manufacturer and they did not help at all. The "engineeur" said it can't be done...
Hmm, we sent men to the moon. Didn't we?
OK, next I pulled the cover off. Pictures are attached.
There are 3 transistors, 3 Zeners, 3 diodes, 2 power diodes and something which looks like power transistor or regulator (rectangular gizmo close to the spade terminals), bunch of resistors,etc.
Me thinking:
Transistors need DC current.
Looks like this unit has a rectifier/voltage regulator-that is a good news.
If I peel off the green glue, perhaps I will be able to check voltage at couple of points and see if I can tap in with 12v DC, bypassing the rectifier.
What say you?
 

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iONic

Joined Nov 16, 2007
1,662
You could just give it a try with two 9V batteries in series (18+V). But otherwise, yes there does seem to be some rectification.
 

Thread Starter

Manfred Von Steinborn

Joined Feb 3, 2009
38
I'm chipping away this green glue, or whatever it is. It is not an epoxy, TG!
Soaking in oil makes the glue more pliable and "waxy". I hope to have the board out of the box tomorrow.
 

praondevou

Joined Jul 9, 2011
2,942
Even if you measure something similar to 12V somewhere it doesn't mean necessarily you can apply 12V at this point.

Since this is a single layer PCB it should be very easy to extract the circuit diagram from it. AFTER you have the circuit diagram and know how it works you can possibly make some changes to it.

If you apply 12V directly somewhere you may damage something... (think of a 12V zener for example, a bit OVER 12V and it's gone)
 

Thread Starter

Manfred Von Steinborn

Joined Feb 3, 2009
38
Well, after a couple attempts I gave up. I soked the board in several different solvents with no good results. Disappointed, i threw it in my tool box and forgot about it.

Couple days ago, I found the PC board and started experimentation, again.

FINALLY, VICTORY!
Combination of 2 hour soak in Acetone and heat turns epoxy into Mozzarella cheese substance!!!
Once heated w/2000W shop heat gun, the green epoxy turned to a greish curd. I was able to remove all of it from the PC back with a thin blade of my pocket knife prying it away and slicing while hot.
Tomorrow, I'll work on the component side of the board.

PS. After 6 hours, the dreadful green goo hardened again, (whatever is left on the PCB). Tomorrow-back to soaking and final clean-up.
 

CDRIVE

Joined Jul 1, 2008
2,219
I don't think that stuff is epoxy. It's far more likely to be potting compound. If the components on this board survive the oil, acetone, other solvents and the 2000W heat gun it's going to be a miracle. Those electrolytics use rubber or neoprene seals. If they're rubber they're probably goo by now.
 

t06afre

Joined May 11, 2009
5,934
I am sure Bill have some 555 based circuits that will do what you want. Your current board is a goner anyway. I am afraid.
 

CDRIVE

Joined Jul 1, 2008
2,219
What is the part number of the device that looks like a power transistor? It's rectangular in the right - top corner of the component side of the board?
 
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Thread Starter

Manfred Von Steinborn

Joined Feb 3, 2009
38
Yeah, it looks bad, but it still functions.
Triac,perhaps, I can not see any number on it. I'll try to use a magnifying glass.

PS. Objective is to convert it from AC to DC.
How much FRN-s I'd have to contribute for someone to do it for me?
 

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t06afre

Joined May 11, 2009
5,934
I found the spec sheet for this device. It state a minimum current of 20mA. That tell me that the switching device most probably will be a solid-state semiconductor. If it is a thyristor or a triac. I can not say. Sorry to say but this device will not work with DC. Save your self some time and use some 555 times or a microcontroller. I guess you can salvage the box and use that
 

Thread Starter

Manfred Von Steinborn

Joined Feb 3, 2009
38
Do you want to use this to evacuate bilge fumes?
I have a simple pre-start bilge timer.
This is for my engine compartment which is a separate box.
On start, I want to delay fans until the engine starts and an alternator is activated/at full speed.
In addition, I want fans to run for 3-5 minutes after shut off to cool of the compartment.
 

Thread Starter

Manfred Von Steinborn

Joined Feb 3, 2009
38
I found the spec sheet for this device. It state a minimum current of 20mA. That tell me that the switching device most probably will be a solid-state semiconductor. If it is a thyristor or a triac. I can not say. Sorry to say but this device will not work with DC. Save your self some time and use some 555 times or a microcontroller. I guess you can salvage the box and use that
Could you please send me the spec sheet?
Thank you.
 
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